Japanese Patent Laying-Open Mo. 2011-78296 (PTD 1) discloses a converter including four transistors and six. diodes to convert AC voltage into high voltage, low voltage, and intermediate voltage. In this converter, among the six diodes, two diodes performing reverse recovery operation are formed of a wide-bandgap semiconductor, thereby achieving reduction of recovery loss in addition, four diodes that do not perform reverse recovery operation are formed of a semiconductor other than wide-bandgap semiconductors, thereby achieving lower costs.